TITRATION OF VINEGAR Flashcards
Technique used to measure the volume of a solution of known concentration that is required to react with a measured amnt. (mass or volume) of an unknown substance in solution
Titration
An instrument used to measure volume
Burette
It is a graduated glass tube about 40cm long with a stopcock on one end. The volume measurement is made by reading the level of fluid in it before and after the titrant is disposed through stopcock
Burette
It is the fluid in the burette
titrant
A solution of known concentration
standard solution
a substance about which something is not known. It is also known as the analyte the substance being identified and measured
unknown
a substance added to the mixture in small amounts, it indicates that the reaction is complete by changing color (endpoint)
indicator
the stage in titration at which the indicator color change is observed, indicating that the reaction is complete
end point
This is a solution of acetic acid in waterr
vinegar
How is the concentration of acetic acid in vinegar may be expressed?
As Molarity (M) or Mass percent
How to calculate for molarity of vinegar?
Moles of acetic acid/volume of vinegar (L)
How to calculate for the mass percent of vinegar?
Mass of acetic acid/mass of vinegar x 100
Step 1:
Before you start titrating, make sure to get the molarity of the ______ that you will use
NaOH
Step 2:
Rinse first the burette with distilled water to remove traces of chemical that may be present in it. Rinse it again with the ___________ solution to make sure that the burette only contains NaOH
standardized NaOH
Step 3:
Fill the burette up to the ________ with NaOH solution and then flush the tip of the burette to remove the trap air bubbles. It is now ready for titration. Make sure to record the initial volume of NaOH before you start for Trial 1
top
Step 4:
Rinse the pipette by drawing in some distilled water using the _________. After rinsing with water, a couple of times
aspirator
Step 5:
Repeat the rinsing using the vinegar solution. After rinsing the volumetric pipet, draw exactly ____ ml _______ solution and transfer it in the flask
5mL vinegar solution
Step 6:
Add _____ mL of distilled water and 5 drops of _______ indicator into the flask. The solution is now ready for titration
- 20 mL
- phenolphthalein
Step 7:
Add NaOH to the flask. Titrate until the solution is ______ (color) which corresponds to the equivalence point. You are near the equivalence point if the _____ color of the solution takes longer to disappear when we swirl the flask
- light pink
- pink
Step 8:
Record the trial volume of the ______ for the first trial. Repeat the titration two or more times
NaOH
